Evil indeed, another evil one would probably be old Wailing Caverns where you have no map, no idea of where you are or where you are going, and we could throw in a couple of extra pointless tunnels and paths just for the hilarities sake. I think it took me until the Burning Crusade to realize that the large weird creature by the final druid wasn't the final boss, and that there was in fact a Murloc boss in there. That dungeon was so confusing...

The main issue I have with the raids at the moment is that they are so bloody linear, there is no choice in what order to kill the bosses. I preferred it the way it was in Ulduar/Naxxramas/ICC. Because of this, I feel a lot of dungeons are ruled out because they too are very linear. For that reason I will pick dungeons that did have choice and were outright awesome:

BRD, an even worse example of Wailing Caverns in terms of getting lost, took me years to find my way in there.

Scarlet Monastery, counting all four, ehm, I mean two dungeons. Could easily be one big cathedral with four wings and lots of awesome bosses.

Scholomance, was another case of easily getting lost until they streamlined it, it's also the dungeon with my favorite boss mechanic, a random member is teleported away from the raid and forced to complete a task (today it could be based on their role), if they fail to do this on time they die, if they mess up the mechanic they die, if they succeed they are let out and can make their way back to the raid.

Something about getting lost in dungeons makes them more interesting and mysterious. ^^

1) Halls of Origination, a lot of bosses, interesting fights as well. A wonderful atmosphere. Great. And the size of it is already quite big.
2) Grim Batol, i love the dark atmosphere there. Bosses that could really be hard once turned into raid bosses.
3) Stonecore as a short raid.
4) The old Stratholme was at the time really amazing. Hard, long and the ambiance / atmosphere was just... so dark.
5) Halls of reflections : really nice dungeon, one of my favorite. Though it would be quite short indeed.
6) Drak'tharon : really love this place. Could be a nice troll only dungeon.
7) The Arcatraz, love this place too.
8) The Shadow Labyrinth.

1) Halls of Origination, a lot of bosses, interesting fights as well. A wonderful atmosphere. Great. And the size of it is already quite big.
2) Grim Batol, i love the dark atmosphere there. Bosses that could really be hard once turned into raid bosses.
3) Stonecore as a short raid.
4) The old Stratholme was at the time really amazing. Hard, long and the ambiance / atmosphere was just... so dark.
5) Halls of reflections : really nice dungeon, one of my favorite. Though it would be quite short indeed.
6) Drak'tharon : really love this place. Could be a nice troll only dungeon.
7) The Arcatraz, love this place too.
8) The Shadow Labyrinth.

Like my erection.

OT: I just remembered what HOO was, I got it mixed up with the Storm Peaks 5mans. Yeah, that place would be cool to turn into a raid.